Diagnostic of rowing performance and technique to optimise the rowing
technique Prof. Dr. Klaus Mattes
Structure
1. How can we test the rowing technique with the help of biomechanical methods?
2. How can we interpret the biomechanical data?
3. Biomechanical feedback in the racing boat
2
Final Race, London 2012
3
DriveCZE
forward position catch
DriveNZL
end of drive feathering, finish position
4
middle of drive end of drive
start of drive start of drive
5
The current mobile measuring and training system
6
Place time [s] number of strokes
SR[1/min]
bh [m]
bm[kg]
Secondn=4
427.1 240.6 33.8±1.3 1.81 ±0.05 72.0 ±4.54
Winnern=4
425.4 234.7 33.1±1.7 1.80 ±0.04 71.5 ±5.04
Overview of the athletes, women, n=8
Final women‘s quadruple scullGerman Championships Berlin,
june 2004
7
100
150
200
250
300
350
Total evaluation, 2000m
Whandle/t2000m [W]
253 16 263 29
Winner Second
8
0
50
100
150
200
250
300
350
400
Comparison winner vs. second place, race time difference < 2s
Handle force [N]
Handle work [J]
Handle power [W]
294 320 226 238 152 165
Winner, n=4 Second, n=4
Handle power [W]
9
Comparison winner and second place, German Championchips 2004,
W4x
C
CB
B
A
A
aboat [m/s2]
Angle [°]
Winner
Second
10
What can we emphasize?
• Rowing technique is an important factor of rowing performance.• It transfers the physical abilities in rowing performance.• The quality of rowing technique in the drive and recovery effect the
race result that is expressed in the curves of the rowing technique.• For the crew it is reflected in the acceleration curve of the boat.• The handle power is only a necessary but not a sufficient condition
for fast rowing.• Rowing technique must satisfy scientific criteria!• Success in competition is not a scientific criterion!• Individual characteristics of internationally successful rowing teams
are often misinterpreted as a further development of rowing technique.
11
Structure
1. How can we test the rowing technique with the help of biomechanical methods?
2. How can we interpret the biomechanical measuring results?
3. Biomechanical feedback in the racing boat
12
…is a biomechanically and physiologically performance-effective solution to the specific task in sculling or sweep rowing, to transfer the physiological and anthropometric capabilities of the athlete via the oar to the boat in such a way that by making maximum use of external conditions and in the prevailing tactical situation a high average speed of the combined boat/athlete system results (Mattes, 2006, p.55).
Rowing technique
13
Sweep rowing techniqueSculling technique
Rowing technique
14
Sculling technique
the same solution for the rowing task,but of course with individual differences
Rowing technique
depends on– different biomechanical properties of the human
musculoskeletal system (strength, endurance, flexibility…)
– tasks in training and racing (i.e. different stroke rates and boat velocity)
– boat class (varying boat velocity and corresponding water resistances)
– oar adjustments (gear ratio, blade shapes and surfaces)
– gender specific, junior training
16
Rowing technique
Rowing technique can be measured via kinematic and dynamic parameters and characteristic
curves.
-100
0
100
200
300
400
500
600
700
800
900 Force [N]
20
40
60
80
100
120
140 Angle[°]
F [N]
[°]
drive recovery
min
min
max
S l
tB tE
Fmax = 810 N
Fmean = 600 N
tdrive = 0.72 s
characteristic curves characteristic values
17
direction of motion
F W F air
F gate
F seat
F gate
-mab Fst
F seatstgateb FFF
airWbb FFFam
F W = total hydrodynamic drag forceF b = net boat force F air = total air drag force
F gate = gate force
-ma b= inertial force
F st = stretcher forceF seat = seat force
m = mass
a b= boat acceleration
drive
Applied forces on a boat
18
direction of motion
F W F air
F gate
F gate
-mab Fst
F stgateb FF
airWbb FFFam
F W = total hydrodynamic drag forceF b = net boat force F air = total air drag force
F gate = gate force
-ma b= inertial force
F st = stretcher force
m = mass
a b= boat acceleration
drive
Applied forces on a boat
19
Applied forces on a boat
direction of motion
F W F air
F seat
-ma b
seatstD
b FFFF
recovery
F st
F W = total hydrodynamic drag force
F air = total air drag force
-ma b= inertial force
m = mass
a b= boat acceleration
airWbb FFFam
F b = net boat force
F st = stretcher forceF seat = seat force
20
Applied forces on a boat
direction of motion
F W F air
-ma b
stD
b FFF
recovery
F st
F W = total hydrodynamic drag forceF b= net boat force F air = total air drag force
-ma b= inertial force
F st= stretcher force
m = mass
a b= boat acceleration
airWbb FFFam
21
2 3 4 5 6time [s]
- 2
- 6
0
2
6 400
200
0
- 200
ab [m/s2] Fb [N]
Comparison of curves of boat-force (Fboat) against boat-acceleration (aboat)
using a single (1x) as an example
F boat
a boat
drive recovery
22
No. 5No. 6
No. 7
No. 8
F boat [N]
F stretcher [N]
F gate [N] 8+
Angle [°]
Force-angle curves,four rowers, same stroke rate
23
SR 20SR 24SR 28SR 32500 m
Seat 2 8+
Force-angle curves,one rower, different stroke rates
F boat [N]
F stretcher [N]
F gate [N]
Angle [°]24
Force-angle curves,one rower, different stroke rates
Seat 7 8+
F boat [N]
F stretcher [N]
F gate [N]
Angle [°]
SR 20SR 24SR 28SR 32500 m
25
Synchronisation of video and biomechanical data
26
Important aspects of rowing technique
1. Force curve represents the rower’s signature (Nolte 1979), independently of stroke frequency or the applied force (individual’s rowing technique).
2. The experienced rower has the ability to vary his/her technique in respect of force and movement speed to adapt on varying conditions.
3. There arise typical changes in rowing technique which depend on boat speed and stroke frequency.
4. Rowing technique must be tested under the different demands of training and competition to be able to form reliable conclusions.
5. The difficulty lies in clearly distinguishing the individual manifestations and drawing the right conclusions to be followed in technique training.
27
rear reversal
drivefront reversal
start of drive (sd) middle of drive (md) end of drive (ed)
recovery
Structure of the rowing stroke
slowing downforward slidinghands away
28
Structure
1. How can we test the rowing technique with the help of biomechanical methods?
2. How can we interpret the biomechanical data?
3. Biomechanical feedback in the racing boat
29
Biomechanical parameters of rowing power and technique
parameters and characteristic curves
kinematic dynamic
oar angle ()oar velocity (v handle)
seat position (s seat)seat velocity (v seat)
boat acceleration (a boat)
handle force (F handle)
stretcher force (F stretcher)
boat velocity (v boat)
gate force (F gate)
boat force (F boat)
individual parameter
crew parameter
30
Comparison of biomechanical curves for rowing technique
curves with error
illustrations
ideal curves
v seat
F gate
F stretcher
F boat
v boat
Angle
tmin tmax tmin tmin tmax tmin
d r
r = recovery
d = drive
45
31
Rowing angle and stroke phases
32
Rowing movement structure
min min
wf
33
Characteristic oar angle-time curves
• rhythm ratio (1)• steep or shallow rises
mean high or low oar angular velocity (2)
• plateau indicates a stopping of the oar handle (movement pause) (3)3
2
2
3
[°]
70°
max
stro
ke le
ngth
tmin tmax tmin tmin tmax tmin
min
drive recovery 1
curves with error illustrationsideal curves
34
Characteristic seat-velocity time curves
• unbalanced work by the legs or a stroke phase with over-emphasised start (4) or middle of the drive (5)
• start of sliding (too early or too late and/or too strongly (6)
• sternward movement (too quick or too slow) (7)
• braking (too early or too late) (8)
• flowing forward direction reversal (no pause in the seat movement) ( 9)
curves with error illustrations
drive recovery
tmin tmax tmin tmin tmax tmin
45
ideal curves
v seat
35
Stroke length, stroke angles and seat position
Data Sl [°]
φi [°]
φwc [°]
twc [s]
φx [°]
φwf [°]
twf[s] [m] [m]
M1x 110 24 1 0.04 134 3 0.07 0.6 0.53
M2x 110 24 1 0.04 134 3 0.07 0.6 0.53
M4x 110 24 1 0.04 134 3 0.07 0.6 0.53
LM2x 106 28 1 0.04 134 3 0.07 0.54 0.5
M2- 90 36 1.5 0.05 126 4 0.09 0.6 0.54
M4- 90 36 1.5 0.05 126 4 0.09 0.6 0.54
M8+ 90 36 1.5 0.05 126 4 0.09 0.6 0.54
LM4- 86 38 1.5 0.05 124 4 0.09 0.56 0.5
Senior men average values over 2000m
seatdrivesseat
cycles
36
Data Sl [°]
φi [°]
φ wc [°]
twc [s]
φ x [°]
φ wf [°]
twf[s] [m] [m]
unit ° ° ° s ° ° s m m
W1x 106 28 1 0.04 134 3 0.07 0.52 0.48
W2x 106 28 1 0.04 134 3 0.07 0.52 0.48
W4x 106 28 1 0.04 134 3 0.07 0.52 0.48
LW2x 102 30 1 0.04 132 3 0.07 0.48 0.44
W2- 86 36 1.5 0.05 122 4 0.09 0.5 0.46
W8+ 86 36 1.5 0.05 122 4 0.09 0.5 0.46
Stroke length, stroke angles and seat position
seatdrives
Senior women average values over 2000mseatcycles
37
Synchronisation of video and biomechanical data
38
longitudinal component
blade-force
Fhn
Fhl
Fh
Fgl
FDL
Fbl
Fst
Fhl
Fhn
F glFgn
Fbl
stretcher-force
longitudinal componentnormal component
normal component
Fst
Fg
Fgn
φFh
φFh angle of pull direction
Fh handle-force
Fg gate-force
stretcher
handle
Handle and gate force
Fstn normal componentFstt transverse component
Fstn
Fstt
39
Characteristic handle force-time curves
• complete characterisation of the pattern of the stroke structure
– in idealised form (10) – or with emphasis on the start
(11)– or the middle (12)– or the finish of stroke (13).
• the variation of force dynamics with time
– at the beginning or the end of the drive (14)
– force increase (15), – magnitude of the applied force
(16)• air shot at the catch (17)• length of the finish (18)• sharpness and speed of
extraction (19)
tmin tmax tmin tmin tmax tmin
drive recovery
F gate
curves with error illustrationsideal curves
40
Typical values of the handle power and its components
Senior men on average over 2000m
Datacycle drive
bh SR P handle P handle W handle F handle v handle t drive s handle
unit m 1/min W W J N m/s s m
M1x 1.96 37 505-605 1040-1300 820-980 520-620 2.00-2.10 0.66-0.70 1.58
M2x 1.96 38 510-610 1035-1300 805-960 510-610 2.03-2.13 0.64-0.67 1.58
M4x 1.96 39 520-620 1025-1290 800-940 500-600 2.05-2.15 0.62-0.65 1.58
LM2x 1.84 38 385-480 810-1065 610-760 400-500 2.03-2.13 0.64-0.70 1.52
M2- 1.98 38 380-475 800-1050 590-740 400-500 2.00-2.10 0.66-0.70 1.50
M4- 1.98 39 385-485 810-1065 580-730 395-495 2.05-2.15 0.64-0.67 1.50
M8+ 1.98 40 390-490 820-1080 575-725 390-490 2.10-2.20 0.60-0.63 1.50
LM4- 1.87 39 315-415 700-965 480-640 340-450 2.05-2.15 0.64-0.67 1.4241
Typical values of the handle power and its components
Senior women on average over 2000m
Data
cycle drive
bh SR P handle P handle W handle F handle v handle t drive s handle
unit m 1/min W W J N m/s s m
W1x 1.80 35 480-570 550-780 430-580 290-390 1.90-2.00 0.68-0.71 1.48
W2x 1.80 37 255-350 540-770 415-560 280-380 1.92-2.02 0.66-0.69 1.48
W4x 1.80 38 260-360 545-780 415-560 280-380 1.95-2.05 0.64-0.67 1.48
LW2x 1.68 36 205-265 460-625 340-440 240-310 1.92-2.02 0.62-0.65 1.42
W2- 1,82 36 250-320 570-760 420-530 300-380 1.90-2.00 0.66-0.69 1.40
W8+ 1.82 38 260-330 580-780 410-520 290-370 2.00-2.1 0.62-0.65 1.40
42
Evaluation of the handle power
Total evaluation Handle power in the stroke cycle (e.g. over 2000m)
direct effect • stroke rate• handle power in the drive phase • handle work in the drive phase • handle force in the drive phase • handle velocity in the drive phase • effective stroke length• drive time
SRW handle
F handle
s handle
v handle
Slt drive
indirect effect and details • handle force in- start of drive- middle of drive- finsh of drive
• handle velocity in - start of drive- middle of drive- finsh of drive
• stroke length- minimal angle - maximal angle
• seat velocity in the drive phase- start of drive- middle of drive
F handle
v handle
s lφ min
φ maxv seat
handlecycleP
43
Characteristic stretcher force-time curves
• slowing down the trunk swing via the stretcher, 20)
• trunk is not recovered speedily after the hands away (pause) (21)
• starting the sliding too harshly (22)
• change on the stretcher from pulling to pressure force (23)
• strong braking of the forward sliding movement (24)
F stretcher
tmin tmax tmin tmin tmax tmin
drive recovery
curves with error illustrationsideal curves
2122
44
Characteristic values (Fstretcher)recovery
90 100 120704030 50 60 80 110 13020
0
200
400
600
800
Fmin
recoverydrive
Stretcher force [m/s]
Angle [°]
-200
-400N0Fst
45
Evaluation of the recovery phase through stretcher force and seat
velocity valuesCharacteristics of the recovery phase
direct effect • minimum of the stretcher force in the recovery [N]
• oar angle to the point of zero stretcher force (Chance the stretcher force of pull to pressure force in the recovery) [°]
• average seat velocity in the recovery [m/s]
indirect effect and details
• seat displacement [m]
• minimal seat velocity in the recovery (maximum of the seat velocity in the forward direction) [m/s]
stretcherminv
N0Fst
seatv
seatsseatminv
46
Characteristic boat force-time curves
• discontinuities front reversal (25)
• late or interrupted development of boat-force in the start of drive (26)
• negative boat force at the finish (27)
• negative boat force in the back reversal (28)
• starting the sliding too harshly (22)
• change on the stretcher from pulling to pressure force (23)
• strong braking of the forward sliding movement (24)
F boat
tmin tmax tmin tmin tmax tmin
drive recovery
curves with error illustrationsideal curves
2223
24
47
Characteristic boat speed-time curves
• boat speed starts to increase (29),
• increase is continuous or with interruptions (30)
• In the recovery phase the effects of
– extraction (31)– forward sliding (32)– slowing down (33)– front reversal and catch (34)
V boat
tmin tmax tmin tmin tmax tmin
drive recovery
curves with error illustrationsideal curves
48
Characteristic values (vboat)
Test Strokes SR[1/min]
sb[m]
vb[m/s]
vbmin[m/s]
vbmax[m/s]
∆vb[m/s]
∆vb[%]
vbφmin[m/s]
vbφmax[m/s]
0047 209 36.9 9.24 5.66 4.29 5.62 2.68 47.6 5.62 5.77
90 100 120704030 50 60 80 110 130202.0
3.0
4.0
5.0
6.0
7.0
8.0
vb
vbmin
vbmax
vbφmax
vbφmin
∆vb
recoverydrive
boat velocity [m/s]
angle[°]
49
Characteristic values (vboat)
Test Strokes SR[1/min]
sb[m]
vb[m/s]
vbmin[m/s]
vbmax[m/s]
∆vb[m/s]
∆vb[%]
vbφmin[m/s]
vbφmax[m/s]
0047 10 20.0 12.65 4.21 3.18 4.32 1.44 34.2 3.92 4.49
0047 10 24.5 11.57 4.72 3.60 4.78 1.73 36.8 4.50 4,97
0047 10 29.2 10.51 5.12 3.95 5.14 2.04 39.9 4.88 5.33
0047 209 36.9 9.24 5.66 4.29 5.62 2.68 47.6 5.62 5.77
Boat velocity depends on the stroke rate (SR)
50
Evaluation of boat velocity fluctuation
Total evaluation • average boat velocity [m/s]
• innercycle boat velocity fluctuation– absolute [m/s]– as a percentage of the average boat
velocity [%]
direct effect • stroke rate [1/min]
• minimum boat velocity [m/s]
• maximum boat velocity [m/s]
SR
indirect effect and details
• boat velocity during minimum oar angle [m/s]
• boat velocity during maximum oar angle [m/s]
boatminv
boatminv
boatmaxv
boatmaxv
boatv
boatv
51
The diagnosis of rowing technique faults
• Identification of a divergence by comparison with an ideal pattern
• During which oar-angle sector does the deviation appear?
• Which peculiarities do the other characteristic curves in the corresponding rowing phase exist?
• What effect is this having on the main aim (boat speed)?• Which faulty movement is hiding itself behind the
divergence?• Formulation of precise movement instructions for
oarsmen and crew.
52
Biomechanical feedback in the racing boat
53
-100
100
300
500
700
900
1100
0 200 400 600 800 1000
time [ms]
F [N]
-100
100
300
500
700
900
1100
0 200 400 600 800 1000
time [ms]
F [N]
Current state of technique
feedback-training
learning progress
Intention: Removal of faults in rowing technique
e.g. the dynamic time structure
54
Reasons for biomechanical feedback
• Some mistakes in rowing technique are hard to eliminate (force structure).
• Kinaesthetic information is unconsciously.• Force patterns are difficult to observe by
the coach. • Coach and athlete need more quantitative
information with higher precision.
55
Trainer‘s displayAthlete‘s displays
Telemetry
56
MMS 2000 - Routineeinsatz3.2 Weiterentwicklung PCS SportlerFeedback display
57
MMS 2000 - RoutineeinsatzFeedback display
58
Feedback training procedure
• Before feedback training: biomechanical analysis of technique to identify the objectives of feedback training
• In feedback training: the athletes are asked to vary the movement in order to change a technical feature. The athlete monitors and regulates the movement with the help of objective feedback
• If the athlete succeeds, the objective feedback information is withdrawn step by step. The athlete learns to produce the altered movement pattern without external feedback
• Retention tests: the altered movement is stable under competitive conditions and without objective feedback
59
Comparison between Pre-test und 1. TU, 4x, No. 4, stroke side, stroke rate 20 [1/min]
Angle [°]
Forc
e [N
]
Pre-test
-200
0
200
400
600
800
20 40 60 80 100 120 140
60
Angle [°]
Forc
e [N
]
Pre-test 1. TU with display
1. TU without Display
-200
0
200
400
600
800
20 40 60 80 100 120 140
Comparison between Pre-test und 1. TU, 4x, No. 4, stroke side, strokerate 20
61
Comparison between pre-test and third
training unit (TU), 4x, SR 20
Forc
e [N
]
Angle [°]
Acc
eler
atio
n [m
/s2 ] pre-test
third TU displaythird TU no display
Seat 4, stroke side
-200
0
200
400
600
800
20 40 60 80 100 120 140
-5
-4
-3
-2
-1
0
1
2
3
4
20 40 60 80 100 120 14062
SR = stroke rate d = with display nd = no display
Gate-force-angle curve for an athlete before, during as well as after feedback
before feedback during and after feedback
Angle [°] Angle [°]
SR 20 dSR 24 dSR 28 dSR 30 dSR 20 ndSR 24 ndSR 28 ndSR 30 nd
SR 20SR 24SR 28SR 30
63
first test
feedback training with display
training without Display
600400200
0
600400200
0
600400200
0
Force [N]
t [s]stroke sidebow side
female, 4x, No. 1
6 9
Comparison of the first test and deviation of intervention
64
Angle [°]
No. 1No. 2No. 3No. 4
first testSR=30 1/min
feedback trainingSR=30 1/min
Force [N]
-200
0
200
400
600
800
1000
1200
20 40 60 80 100 120 140
-200
0
200
400
600
800
1000
1200
20 40 60 80 100 120 140
Approach using stroke length in big boats, N=4
65
Feedback training
• Information about various aspects of technique in the propulsive and recovery phases, like – Spatial attributes of the stroke length– Space-time attributes of the oar and
body movement– Dynamic-time attributes of the force
applied to the handle and stretcher– Attributes of the boat movement (speed
and acceleration)66
Reinforce strokes with positive characteristics
Angle [°]
negative
positive
F gate [N]
Positive and negative force curve characteristics for individual strokes
20 40 60 80 100 120-200
0200400600800
10001200
67
Feedback training
short intervention(2-4 TU)
long intervention (>10 TU)
fine adjustment in crew boat
error removal in crew boat
technique-practice training(reinforcement of emerging
movement pattern)
technique-acquisition training (unlearn and learn anew)
68
For more information
Altenburg D, Mattes K & Steinacker J
Manual for Rowing TrainingTechnique, High Performance and Planning
ISBN: 978-3-7853-1828-7
69
Diagnostic of rowing performance and technique to optimise the rowing
technique Prof. Dr. Klaus Mattes